Some recent discussions regarding difficult to care for Butterflyfish in reef aquariums has spurred me to go ahead and share some of my ramblings on my favorite genus. Also, this editorial by Terry Siegel from last year, where he updates us on the Chaetodon ulietensis he houses in his 700g reef has popped up sub-discussions [...]
Some recent discussions regarding difficult to care for Butterflyfish in reef aquariums has spurred me to go ahead and share some of my ramblings on my favorite genus. Also, this editorial by Terry Siegel from last year, where he updates us on the Chaetodon ulietensis he houses in his 700g reef has popped up sub-discussions across various forums–Are they reef safe? This is a difficult question to answer, but hopefully this will provide some insight.
We know the behavior of fish can and usually does change in captivity, however, looking at their wild diets is one of the best starting point for aquarists considering adding a risky fish to their captive reef.
A study by Morgan S. Pratchett (2005) on the Dietary Overlap of Chaetodontids at Lizard Island shows that among the 20 C. ulietensis observed, they received 20.6% of their diet from Hard Corals and 26.85% from Soft corals. A near 50% contribution towards their diet coming from corals raises some serious questions. Some aquarists have had success with this fish in reef aquariums particularly for nuisance anemone (e.g. Aptasia) control, but let’s take a look at two other commonly available butterflies that may be a safer addition to your reef–Chaetodon auriga & Chaetodon vagabundus.
Based on the same Dietary Overlap study these readily available Butterflyfish appear to be much better reef tank inhabitants
- Of the 104 C. auriga observed their diet consisted of 3.61% Hard Corals and .25% Soft Corals.
- Of the 110 C. vagabundus observed1.51% Hard Corals and 0.0% Soft Corals made up their diet.
The study classifies both as non-coral feeders, noting their diets primarily consisted of “imperceptible prey items” from carbonate pavement and coral rubble. Closely related, C. auriga and C. vagabundus both fall within the Rabdophorus subgenus, but have different reputations among aquarists.
The Threadfin Butterfly, C. auriga, is one of the hardiest Chaetodonts available. They have a wide range and can be found in terrific collecting locales such as Hawaii. Best of all they are affordable, with a price of ~$20-$40.
Photo by OCVA
While the diet numbers for the Threadfin Butterfly above are favorable we must look at other data before considering their addition to a reef aquarium. With such a large range, we do expect some variance in diet. Based on the stomach analysis of 13 specimens collected in the Spring and Summer months of Minatogawa, in Okinawa Japan, it was found C. auriga feeds on a mix of Anemones, Polychaetes, Scleractinian Coral Polyps, Hydroids, and Algae (Sano, Shimizu, & Nose 1984).
Specifically worth noting, after the analysis it was found:
- 10 of the 13 contained Anemones, on average making up 34% of total food volume.
- 7 of the 13 contained Scleractinian Coral Polyps making up 18% of total food volume.
While these percentages are averages among those containing the food item, when compared with the results of Pratchett (2005) there are some obvious differences. If we look at another study, Hiatt and Stratsburg (1960), we find that C. auriga fed predominately on filamentous algae and benthic invertebrates. When contrasted to Sano et. al (1984) in Okinawa, we see that C. auriga rarely fed on algae. In fact, it only made up 1% of the total food volume! This minimal algae feeding by C. auriga has also been noted in Hawaii (Hobson 1974) and the Red Sea (Harmelin-Vivien & Bouchon-Navaro 1983).
Chaetodon vagabundus video by Tanaka
The Vagabond Butterfly, Chaetodon vagabundus, has a mixed record with aquarists. However, if collected and handled properly they can settle in under an advanced keepers care. Like the Threadfin, the Vagabond butterfly is readily available and ranges in price from ~$20-$40.
Based on stomach analysis we see the diet of this fish in Okinawa is dominated by Sea Anemones–making up 48% of total food volume. Stony coral polyps and algae also maketheir presence at 8% and 7% respectively (Sano, et. al 1984). Again we see differences based on location as Hiatt and Stratsburg (1960) found this species to feed only on coral polyps and algae in the Marshall Islands!
Sidenote:
Pratchett (2005) made an observation regarding feeding on corals worth highlighting that I have witnessed first hand with Chaetodontids as well as Pomacanthids:
“Aside from feeding on coral pavement, non-coral feeders occasionally fed on hard-corals, soft-corals and other macro-invertebrates. When feeding on hard corals, C. auriga, C. ephippium, and C. vagabundus fed mostly on damaged or injured colonies.”
And more specificly regarding Chaetodon auriga:
“For C. auriga, only 11 of 104 individuals fed on hard-corals, and most of these individuals took just one or two bites from hard-corals. However, three different individuals were observed feeding intensively on recently damaged colonies of Lobophyllia hemprichii. These individuals spent up to 90 min feeding exclusively on a single damaged colony.”
Damaged fleshy corals, are irresistible to most Butterflyfish. There are significant risks to keep such tempting “LPS” corals, but, if you are willing to take such risks place them in areas where they are not prone to fall or see physical damage. From my own observations, other corals at risk with Chaetodonts include Trachyphyllia, Wellsophyllia, Zoanthus, and Palythoa species.
Tempting snacks for any Butterflyfish
With both C. auriga and C. vagabundus, we can see their diet can vary drastically depending on location and available food sources. As many of these studies strongly hint at, Chaetodonts coevolve with the reefs and their specific food sources. This variance in diet dictated by a close relationship with corals is a repeating pattern among many Chaetodontids that I will explore and share in the future.
Maybe you’re thinking that the differences in diet based on location can influence success in captive reef aquaria? That may or may not be, further investigation will be needed. It is likely a result of the food available given the environment and changes in overall reef health… and if anything is a testament to the amenability of Chaetodon auriga and Chaetodon vagabundus.
As we learn more about the feeding behavior of Butterflyfish, especially corallivore species, we will make large strides in their captive care.
Sources:
Fessler, J.L. & Westneat, M.W., 2007. Molecular phylogenetics of the butterflyfishes (Chaetodontidae): Taxonomy and biogeography of a global coral reef fish family. Mol. Phylogenet. Evol. 45(1): 50-68.
Hiatt, R.W. and D.W. Strasburg, 1960. Ecological relationships of the fish fauna on coral reefs of the Marshall Islands. 89-90.
Pratchett, M., 2005. Dietary overlap among coral-feeding butterflyfishes (Chaetodontidae)
at Lizard Island, northern Great Barrier Reef. Marine Biology: 373-382.
Reese ES, 1981. Predation on corals by fishes of the family Chaetodontidae: implications for conservation and management of coral reef ecosystems. Bull Mar Sci 31:594-604
Sano, M., Shimizu M. & Nose, Y., 1984. Food Habits of Teleostean Reef Fishes in Okinawa Island, Southern Japan . The University of Tokyo.
